직각자

Square

직결구동

Direct Drive

직교류형열교환기

Cross Flow Regenerator, Cross Flow Heat Exchanger

직류

Direct Current : DC

직류아크용접

DC Arc Welding

직립기관

Vertical Engine

직립선수

Vertical Stem, Upright Stem

직립용접

Vertical (Position) Welding

직립형보일러

Vertical Boiler

직선선수

Straight Stem